A5036193204- Marine and coastal ecosystems
- Marine Biology and Ecology Research
- Geology and Paleoclimatology Research
- Geochemistry and Elemental Analysis
- Heavy metals in environment
- Isotope Analysis in Ecology
- Microbial Community Ecology and Physiology
- Paleontology and Stratigraphy of Fossils
- Mercury impact and mitigation studies
- Diatoms and Algae Research
- Arsenic contamination and mitigation
- Methane Hydrates and Related Phenomena
- Oceanographic and Atmospheric Processes
- Groundwater and Isotope Geochemistry
- Marine and environmental studies
- Ocean Acidification Effects and Responses
- Analytical chemistry methods development
- Silicon Effects in Agriculture
- Marine Bivalve and Aquaculture Studies
- Atmospheric and Environmental Gas Dynamics
- Marine Biology and Environmental Chemistry
- Selenium in Biological Systems
- Coral and Marine Ecosystems Studies
- Heavy Metal Exposure and Toxicity
- Marine Sponges and Natural Products
Australian National University
2016-2025
University of Washington
2023
University of Plymouth
2022
University of Geneva
2021
Canberra (United Kingdom)
2015-2018
National Institute of Water and Atmospheric Research
2002-2011
University of Canberra
2000-2006
University of Otago
1999-2005
University of Liverpool
2000-2001
Commonwealth Scientific and Industrial Research Organisation
2001
The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of international programme, and contains measured quality controlled before end 2016. IDP2017 includes from Atlantic, Pacific, Arctic, Southern Indian oceans, with about twice volume previous IDP2014. For first time, for a large suite biogeochemical parameters as well aerosol rain characterising atmospheric trace element isotope (TEI) sources. TEI in are by careful assessment intercalibration...
An improved knowledge of iron biogeochemistry is needed to better understand key controls on the functioning high‐nitrate low‐chlorophyll (HNLC) oceanic regions. Iron budgets for HNLC waters have been constructed using data from disparate sources ranging laboratory algal cultures ocean physics. In summer 2003 we conducted FeCycle, a 10‐day mesoscale tracer release in SE New Zealand, and measured concurrently all (with exception aerosol deposition) to, sinks from, rates recycling within,...
Diatom blooms play a central role in supporting foodwebs and sequestering biogenic carbon to depth. Oceanic conditions set bloom initiation, whereas both environmental ecological factors determine magnitude longevity. Our study reveals another fundamental determinant of dynamics. A diatom spring offshore New Zealand waters was likely terminated by iron limitation, even though diatoms consumed <1/3 the mixed‐layer dissolved inventory. Thus, duration were primarily competition for between...
High-sensitivity measurements reveal variation in surface ocean phosphate, leading to a new model for nutrient cycles.
We report data on the isotopic composition of cadmium, copper, iron, lead, zinc, and molybdenum at GEOTRACES IC1 BATS Atlantic intercalibration station. In general, between lab within‐lab precisions are adequate to resolve global gradients vertical this station for Cd, Fe, Pb, Zn. Cd Zn isotopes show clear variations in upper water column more subtle deep water; these attributable, part, progressive mass fractionation by Rayleigh distillation from biogenic uptake and/or adsorption. Fe...
We have prepared and calibrated a large volume of pure, concentrated homogenous zinc standard solution.
Abstract Mesoscale eddies are ubiquitous in the iron-limited Southern Ocean, controlling ocean-atmosphere exchange processes, however their influence on phytoplankton productivity remains unknown. Here we probed biogeochemical cycling of iron (Fe) a cold-core eddy. In-eddy surface dissolved Fe (dFe) concentrations and were exceedingly low relative to external waters. Fe-to-carbon uptake ratios elevated 2–6 fold, indicating upregulated intracellular acquisition resulting dFe residence time ~1...
Abstract The cycling of calcium carbonate (CaCO 3 ) plays a significant role in deep‐water carbon sequestration and affects the buffer capacity upper ocean for absorbing atmospheric CO 2 . This study investigates dissolved (Ca) potential alkalinity (PA) as tracers CaCO Southern Ocean. correlation between PA Ca concentrations subantarctic polar waters supports their use effective process dissolution precipitation. Estimates particulate inorganic export flux based on concentration reveals...
Around 30% of oceanic waters are high nitrate low chlorophyll (HNLC) where iron levels limit algal growth. HNLC have mainly been studied using shipboard and lab experiments. Since 1997, remote‐sensing phytoplankton via SeaWiFS Ocean Color has permitted monitoring the constancy this “HNLC condition,” i.e., spatial homogeneity temporal variability over annual cycles. These trends can be exploited, as episodic inputs should conspicuous by subsequent expression iron‐elevated stocks. Subantarctic...
Environmental context. Concern over the presence of antimony (Sb) in environment because chemical similarities with arsenic (As) has prompted a need to better understand its environmental behaviour and risks. The present study investigates bioaccumulation uptake highly contaminated stream near Hillgrove antimony–gold mine NSW, Australia, reports high Sb (and As) concentrations many components ecosystem consisting three trophic levels, but limited into aboveground parts riparian vegetation....
Significance The supply and bioavailability of dissolved iron sets the magnitude surface productivity for approximately 40% global ocean; however, our knowledge how it is transferred between chemical states pools poorly constrained. Here we utilize isotopic composition particulate to fingerprint its transformation in ocean by abiotic biotic processes. Photochemical biological reduction dissolution appear be key processes regulating marine biota. Iron isotopes offer a new window into...
Despite recent advances in observational data coverage, quantitative constraints on how different physical and biogeochemical processes shape dissolved iron distributions remain elusive, lowering confidence future projections for iron-limited regions. Here we show that is cycled rapidly Pacific mode intermediate water accumulates at a rate controlled by the strongly opposing fluxes of regeneration scavenging. Combining new sets within watermass framework shows multidecadal accumulation much...
Despite the potential of stable chromium (Cr) isotope compositions as a proxy for past changes in oceanic redox conditions, detailed understanding processes that govern their spatial distribution modern ocean is still lacking. Here, we report seawater Cr and concentrations from uppermost 1000 m water column Southern Ocean. The survey includes cross-frontal transect Tasmania to Antarctica, sites near Antarctic ice-edge vicinity Balleny Islands, well Drake Passage. Although coastal influence...
Iron (Fe) is an essential micronutrient that limits primary productivity throughout the surface of Southern Ocean. Here, we present first high-resolution depth profiles for dissolved Fe and isotope ratios (δ56Fe) from all major zones Ocean, collected during Antarctic Circumnavigation Expedition in austral summer 2017. Open-ocean waters are characterized by remarkably high δ56Fe values (up to +1.6‰) very low concentrations (<0.05 nmol kg−1). We attribute elevated above ferricline effect...
Abstract Carbon dioxide removal (CDR) and emissions reduction are essential to alleviate climate change. Ocean macroalgal afforestation (OMA) is a CDR method already undergoing field trials where nearshore kelps, on rafts, purposefully grown offshore at scale. Dissolved iron (dFe) supply often limits oceanic phytoplankton growth, however this potentially rate-limiting factor being overlooked in OMA discussions. Here, we determine the limiting dFe concentrations for growth key physiological...